Evaluation of the GPR frequency spectra in asphalt pavement assessment

Abstract

Ground penetrating radar (GPR) is frequently used in pavement assessments, mainly using the evaluation of wave travel times. However, GPR data provide further information that could be used in order to determine the inner conditions and characteristics about materials. In this paper, the possible analysis of the frequency spectrum of GPR signals is analysed and discussed. Several tests were carried out in a portion of a highway in two different stages of its service life. Results highlight the relationship between the shape of the spectrum and the frequency signature with the structure and conditions of the pavement.Preprin

Quantitative Attribute Analyses with Ground Penetrating Radar for Infrastructure Assessments and Structural Health Monitoring

“…In civil engineering, GPR is applied to map and locate utilities [7,8,9], monitor and inspect concrete structures for defects and anomalies in the service of civil infrastructure SHM and life-cycle management (e.g., [10]). Specifically, GPR has been used for damage identification in different ages and mixes of concrete [11], corrosion detection and prevention [12,13], robust estimates of pavement thickness [14,15,16] and identification of voids and other defects in civil structures [10,17]. Some work is being done on estimating and tracking the evolution of volumetric water content and dielectric properties, but mainly in the interest of understanding early age concrete hydration [18,19,20].…”

GPR Spectra for Monitoring Asphalt Pavements

“…For example, some researchers showed that non-destructive technologies are not able to identify debonding between asphalt layers because of an inadequate tack coat execution. However, GPR can be used to detect this distress when moisture is trapped in the interface [41,42]. In addition, some researchers discuss the ability of non-destructive technologies to detect an inadequate tack coat execution [41].…”

“…The spectrum is also sensible to clay content in the pavement base, and several studies point to the possibility of using the peaks displacement to detect changes in clay content [74]. The work of Pedret et al [42] analyses a section of flexible pavement by evaluating the changes in the spectrum according to the thickness of the bituminous mixture layers, the moisture and the detachment between layers. Based on the variations observed in the bandwidth and in the amplitude of the frequency spectrum maximums, the use of GPR is proposed to define stretches of road in accordance with the parameters observed in the frequency spectrum.…”

“…The preliminary tests in selected areas show an interesting correlation between the form of the amplitude spectrum and the structural condition of the pavement [42]. However, in these first analyses, the records were studied at certain points by evaluating individual traces.…”

Future Trends in Transport Infrastructure Monitoring

“…The signal processing in frequency domain is a potential tool for detecting changes in the characteristics of the material tested, which is not limited to thickness only. It was applied at research level for detecting damage in airport pavements, using ground coupled antennas [7]. The application of this approach to the assessment of railway infrastructure is presented in this study as an example of possible infrastructure monitoring at the network level [8].…”